The rock under the Dome of the Rock building was originally bedrock under the Ulam (Porch), the threshold, the eastern part of the Heichal (Holy Place), and the adjacent northern side rooms. This description of the rock has never been stated before by anyone except myself. Either the rock was the site of the altar, or the site of the Holy of Holies, or else it was bedrock no where near the actual temple building. If you want to discover how I came to this conclusion, you can read my papers beginning with this one:
Jerusalem temple location paper
This latest revision of my paper has been months in the making.